Control apparatus



H. F.. PORTER.

CONTROL APPARATUS. APPLICATION FILED JUNE 3. 1919.

1,377,274. Patented May 10,1921.

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H. F. PORTER.

CONTROL APPARATUS.

APPLICATION FILED JUNE 3, 1919.

1,377,274. Patented May 10,1921.

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H. F. PORTER.

CONTROL APPARATUS.

4 APPLICATION FILED JUNE 3,1919. I 1 ,377,274. Patented May 10, 1921.

3 SHEETS-SHEET 3.

ATTORNEY.

UNITED STATES PATENT OFFICE;

HARRY F. PORTER, 0F

TRENTON, NEW JERSEY, ASSIGNOR TO PYROLECTRIC INSTRU- MENT 00., OF TRENTON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

. CONTROL APPARATUS.

Application filed June 3, 1919.

My invention resides in control or recording apparatus, preferably operating upon null method, comprising a thermionic device, as anaudion or equivalent, which responds to and amplifies electric current or energy, particularly when of relatively small or minute magnitude, resulting from the subjection of a thermo-couple, resistance, or other suitable means, to changes in temperature or any other suitable or desired condition;

In accordance with my invention there is produced a current or current change in response to a varying condition, as temperature, and as a result of such current or cur-' rent change the potential of a grid-like element is caused to effect a change in a thermionic or space current whose quantity at tains different magnitudes for different grid potentials, and the plate or anod CiICHlt,

currents of different magnitudes effect a control of mechanism controlling either production of a record or any" suitable apparatus,.such, for example, as will in turn cause a change in the condition to which the grid potential is responsive.

For an illustration of some of the various forms my invention may take, reference is to be had to the accompanying drawings, in which:

Figure 1 is a diagrammatic view illustrating recording apparatus embodying my 1nvention.

Figs. 2, 3 and 4 are diagrammatic Views of modified forms of apparatus embodying my invention.

. Fig. 5 is a view on enlarged scale of part of the structure employed in Fig. 1.

. Fig. 6 is a graphic representation of relation between plate current and grid potential in a thermionic device.

Specification of Letters Patent.

vice, and the grid 9 interposed as usual rent, as battery B Patented May 10, 1921.

Serial No. 301,593.

Referring'to Fig; 1, a potentiometer circuit is employed, as may be any equivalent thereof,'comp1'ising a source of current, as a battery B, connected in series with the resistances R, R and R the last named being adjustable. T represents a junction of a thermo-couple adapted to be subjected to a temperature whose variations are toeffect a record or control. The thermo-junction is connected through leads 1 and 2 with one terminal of the resistance R and switch terminal 8, respectively. The contact a, movable along the resistance R by the nut b actuated by the screw 0 which is in turn rotated by the wheel or pulley d, is connected by conductor 4 to the switch terminal 5. lVith the switch terminals 3 and 5 engage the switch blades 6 and 7 connected, respectively by conductors 8 and 9 with the electron emitting body or filament f of the auidon A or any equivalent thermionic geetween the electron-emitting body or cathode fand the plate or anode p. In the plate or anode circuit is any suitable source 0 current, as battery B and electro-mag-net windings h and i. Cooperating with both sets of electro-magnets is an armature structure e, pivoted at j and adapted to engage the relay contacts 74 and m connected, respectively, through conductors 10 and 11 with electro-magnets n and 0, Whose remaining terminals connect with'a source of ourwhose other terminal connects with the relay armature Upon a stationary pin 79 is pivoted the armature lever Q cooperating with the electro-magnets n and 0. A gear or friction wheel 1' is rotatable coaxially with the pivot and is driven by the pinion or friction wheels 8 adapted to be driven in one direction or the other as itis brought into contact with one or the other of the gears or friction wheels t or u, of which one, as-t, is constantly rotated at uniform speed by a motor or other suitable means, not shown, and wheel at is constantly driven by t. Movable with the nut b is a marker o, as a recorder pen or equivalent, marking upon the sheet of paper w stored in a roll upon roller 'w and advanced past the marker '11 by engagement with the roller 0w which is continuously driven at substantially constant the motor which drives driving of the roller w is indicated by the pulleys a, 00 m and. .90 with which cooperate suitable cords or belts, this being merely a diagrammatic indication of any suitable means for rotating the roller w Movable laterally with respect to the aforesaid wheel or gear 1* are the gears or wheels (5 and y, the former adapted to ro-' tate the aforesaid screw 0 and the latter adapted to rotate the screw 2 to move the nut 3 longitudinally thereof to move the contact y along the resistance R for readjusting or calibrating the potentiometer circuit as hereinafter described. The wheels d and y are pivoted, respectively, at 12 and 13 upon the transversely movable bar or member 14: biased toward the left by the spring 15 and carrying on its other end an armature 16 cooperating with the electro-magnet 17, which latter is in circuit with the battery B and the contact 18 adapted to engage once for each revolution of the wheel t the contact 19 carriedby said wheel and connected to a slip ring 20 upon which bears a brush 21 connected to the other terminal of the magnet 17.

Referring to Fig. 6, there is shown, by way of illustration merely, a characteristic curve of-a thermionic device, ordinates representing anode or plate circuit currents, while abscissae are grid potentials. It is seen that as the potential of the grid be comes more and more positive, the plate or anode current increases.

For any given anode or plate current, as 2, corresponding, fOr example, with substantially zero potential of the grid 9, as when the electro-motive-force of the thermocouple T is equal and opposite to the electromotive-force or fall of potential across that,

portion of the resistance R to the left of the contact a, the effects of the electro-magnets k and 2' in the anode or plate circuit may be made substantially equal and opposite, so that the armature 6 remains in its mid-position indicated. One electro-magnet, as it, may have a greater number of convolutions or turns than the other and be so proportioned that with a predetermined or given plate circuit current, as 2, its magnetic circuit will be saturated, while the same current passing through the lesser number of turns of the'magnet i causes it to produce magnetism substantially equal to the magnetism of themagnet lb, but without saturation of the magnetic circuit of the magnet i.

The operation is as follows:

When the temperature to which the junction T is subjected is such that the electromotive-force produced by the thermo-couple balances the fall of potential across that part of the resistance R to the left of the contact a, the potential of they grid 9 is zero, or any other suitable value if a source of current,

as one or more battery cells, is connected in the grid circuit. In any event, if this balance between the resistance and the thermocouple T obtains, the aforesaid predetermined current 2 exists in the plate circuit and the armature 6 remains in its mid position indicated. If, however, the temperature and electro-motive-force of the thermocouple increase, the fall of potential across the resistance R to the left of the point a is, for example, less than the thermo-couple electro-motive-force, and the potential of the grid 9 becomes, for example, more positive with increase of current in the plate or anode circuit to a value greater than the aforesaid value 2. The magnet it being saturated, this increase of current will produce little or no increase in strength of the magnet h, but on the other hand, the strength of the magnet a will materially increase because its magnetic circuit is not saturated. Accordingly the balance between the magnets li. and i is upset, and the magnet 2' will attract the armature 6 into engagement with the contact is, causing energization of the electro-magnet n, which will then attract toward the right the upper end of the armature g, bringing the wheel .9 into engagement with the wheel u, rotating at substantially uniform speed, thereby causing the wheel d to rotate the screw 0 in such direction as to move the nut b and the contact a toward the right until the fall of potential through the'left hand portion of the resistance R again balances the now increased electro-motive-force of the thermo-junction, whereupon the plate circuit current will re turn to its normal value and the armature 6 will return to its indicated mid position.

In effecting this movement of the nut b the marker 7) has also moved transversely of the record sheet w to produce a record indicating an increase in temperature or electro-motive-force of the thermo-couple.

If the reverse condition obtains, that is, the electro-motive-force of the thermocouple diminishes to a value less than the fall of potential across the left hand portion of the resistance R, the plate circuit current will diminish below the value for a balance, with the result that the magnet 2' will weaken much more than the saturated magnet it and magnet it will accordingly gain'control of and attract armature 6 into engagement with contact m, causing ener ization of magnet 0,-

with' 'the resultl that t e wheel 8 will be brought into engagement with the wheel 2% and accordingly rotate the wheel (I and screw 0 in opposite direction to that above referred to, causing the nut 5, contact a and marker v to move toward the left until balance is again reestablished.

And so on, the apparatus continues to operate automatically,'moving the contact a and marker o backwardly and forwardly,

always seeking a balance between the electro-motive-force of the thermo-couple and the fall of potential through the portion of the resistance R to the left of contact 0..

Where the battery B is not of the nature of a standard cell or a source whose electromotive-force remains constant, as when the battery B is one or more dry. cells, the electro-motive-force-current conditions in the potentiometer circuit as affected by the .battery B will vary from time to time and accordingly introduce errors. To overcome this, the apparatus comprises structure for readjusting the total resistance in series with the battery B to such value that correct amount of current flows therethrough to efiec-t the correct falls of potential across the left hand portion of the resistance R This is accomplished as follows :-Once per revolution of the wheel t the electro-magnet 17 is energized through the contacts 18 and 19, causing attraction of the armature 16, which moves the bar 14 to the right in opposition to the s ring 15. This takes the wheel 03 out of mes or' contact with the wheel 7' and brings wheel 3 into mesh or contact with wheel 7. Simultaneously with the movement of the armature 16 toward the right, the mechanical connection 22 between the armature 16 and the switch 6, 7 moves the switch 6, 7 toward the right, bringing blades 6 and 7 into engagement, respectively, with the contacts 23 and 24, whereby there is brought into the grid circuit, in lieu of the thermo-couple in cooperation with the left hand portion of the resistance R ther 1;-

fore, for a period corresponding with the angular extent of the contact 19, to seek and find a balance, and in so doin the wheel y is rotated in one direction or tie'other as the wheel .9 is in contact with one Or the other of the wheels 23 oru, moving the contact 7f to such point on the resistance"R that the fall of potential across the resistance R due to current from opposite to the electro-motive-force of the vice. In this instance standard cell By this'action the resistance R in series in the potentiometer circuit has been ad usted to a new and correct value. Thereafterj'magnet 17 is deenergized,

switch'6, 7 is returned to position indicated; wheel d resumes its indicated position, and the apparatus again operates as above described.-

In Fig, 2 an automatically controlled rheos tat or resistance structure varies the current through, a fixed resistance to vary the drop of potential'across said fixed resistance to balance the electro-motive-force of the thermo-couple. or

the battery B is conaround nected in circuit with a resistance R 6 5 a variable portionof which is shunted a the battery B is equal and other equivalent devariable ortion of the resistance R in series wit the aforesaid fixed resistance R. and in series with the variable portion of resistance R an". the fixed resistance R is any suitable galvanometer for indicating or recording purposes. For example, the galvanometer may be a DArsonval galvanometer having the movable coil 25 whose pointer or needle 26 carries the marker 7;, ing with the recorder sheet w. In this instance there are movable with the nut' 7) and 0 being again controlled by the armature e cooperating with the plate circuit magnets h and i, as described in connection with Fig. 1. device T is connected in the grid circuit in series with the resistance R, whereby the potential of grid 9 depends upon the electromotive-force of the thermo-couple and the fall of potential across the resistance R due to current from the battery B. The mode of operation is general that described in connection with Fig. 1 in that with rising and falling voltages of the thermo-couple the apparatus is unbalanced'one way or the other, causin movement of the contacts a and a in suc direction as to restore a balance. For such balance at. diiferent temperatures of the thermo-couple difi'erent currents are flowing through the galvanometer coil 25, causing different deflections of the needle 26 and therefore difi'erent transverse positions of the marker 21. In addition to the coil 25 there may be inserted in circuit with the resistances R and .R any number of'galvanometers used either asindicators or recorders, or for any other purposes;

In ig. 3 a ment is employed in which in ad acent arms .on opposite sides of the movable contact or,

thermometer resistance 1, which is subjected to the temperature .to be measured or controlled, and ccordingly varies its resistance in well known manner. cuit of the thermionic device A is connected to the points 28 and 29, that is, in one conjugate conductor of the Wheatstone' bridge in whose other coniaugate conductor is connected the battery In this ca a ha b ati misas pl q 'Witha rise'in temperature there is 'a'r'is'e in resistance of the thennomaeter T ,'causing a difference in potential between the points coiiperat-' The grid; cir- The thermo-couple or other Wheatstone bridge arrange- .ling a marker or any other suitable device.

In Fig. 4 is shown control apparatus whereby there may be automatically main" tained substantially constant current through a resistance or-other translating device. For example, the resistance F may be the resistor of an electric furnace through which it. is desired to maintain a substantially constant current flow from the generator or source G, whose voltage is variable or which fluctuates from time to time. In series with the generator G and the resistance F is a resistance R on which is movable acontact 6 connected to a resistance R on which moves the contact a driven by the wheel 03 associated as before for control by the audion A. A variable portion of the resistance R is connected in shunt to the resistance F and to a variable portion of the resistance R the contact b being manually moved to position to effect the predetermined current value which it is desired shall be maintained in the resistance F. The grid circuit of the audion includes the standard cell 8 and is connected in shunt to the resistance or any desired portion thereof.

In operation, if the current through the' resistance F should vary from the predetermined normal, the voltage of the grid 9 will be changed, eifecting through the magnets h and 2' such a change in the plate or anode circuit current as to cause the wheel d to be moved in suitable direction to move the contact a to such position that the resistance F is suitably shunted to restore the current in the resistance F to the desired value. Thus, for either increases or decreases in the current in the resistance F the wheel at will be rotated in the one direction or the other to restore balance, which balance corresponds with the restoration of current in the resistance F to the predetermined desired amount.

It will be understood that the nut b or any other device moved as by the wheel 03 of any of the arrangements disclosed, or any equivalents thereof, may be used for moving valves, adjusting 'rheostats or effecting any other mechanical operation or control. I

WhatI claim a; 1. The combination with an electrical source of a thermionic device electrically controlled thereby, electrical means for producing a variable efleot in opposition to the effect on said thermionlc device produced by said source, and means controlled by'said I thermionic device for varying said electrical means. 1

2. The combination with an electrical source, of a thermionic device electrically controlled thereby and comprising an electrode Whose potential controls the magnitude of the space current, variable electrical means cooperating with said source to control the potential of said electrode, and means controlled by said thermionic device for varying said variable electrical means.

3. The combination with a temperature responsive device, of a thermionic device electrically controlled thereby, variable electrical means opposing said temperature responsive device in controlling said thermionic device, and means controlled by said thermionic device for varying said variable electrical means.

4. The combination with a temperature responsive device, of a thermionic device electrically'controlled thereby and comprising an electrode whose potential controls the magnitude of the space current, variable electrical means cooperating with said temperature responsive device to control the potential of said electrode, and means controlled by said space current controlling said source, of a thermionic device electrically controlled thereby, variable. electrical means cooperating with said electrical source in controlling said thermionic device, a source of power for actuating said variable means, and means controlledby the space current of said thermionic device controlling connection between said variable electrical means and said source of power.

7. Thecombination with a temperature responsive device, of a thermionic device having an electrode whose potential controls the space current'of said thermionic device, variable electrical means opposingsaid temperature responsive device in controlling the potential. of said electrode, and means controlled by the space current of said thermionic device controlling said variable electrical means. v

' 8. The combination with an electrical source, ofa thermionic device, variable electrical In'eans' cooperating with said source 'in controlling said thermionic device, el'ecrent of said thermionic device controlling said variableelectrical means.

9. The combination with an electrical source, of a thermionic device, variable electrical means cooperating with said electrical source in controlling said thermionic device, electro-magneticmeans responsive, respectively, to increases and decreases in the space current of said thermionic device, and 'a'source of power controlled by said electromagnetic means for actuating said variable electrical means. i

. 10. The combination with a temperature responsive 'device, of a thermionic device, variable electrical means coo. erating with said temperature responsive evice in controlling said thermionic device, elect'ro-magnetic means responsive, respectively, to increases and decreases in the space current ofsaid thermionic device controlling said variable electrical means.

. 11. The combination with a temperature responsive device, of a thermionic device, variable electrical means cooperating with said temperature responsive device in controlling said thermionic device, electro-magnetic means responsive, respectively, to increases and decreases in the space current of said thermionic device, and a source of power controlled by said electro-magnetic means for actuating said variable electrical means.

12. The combination with means responsive to temperature changes for efiecting potential differences, of a thermionic device electrically .controlled thereby and comprisk ing an electrode whose potential controls the space current means for producing a variable potential in opposition to the potential difference efiected by' said temperature responsive device and cooperating therewith to control the potential of said. electrode, and means controlled ple, of a potentiometer said space current controlling said means. I

with a thermo-coucomprising a variable resistance to produce a fall of potential equal and opposite to the electro-motiveforce produced by said thermo-couple, a thermionic device having an electrode whose potential depends upon the diiierence of the electro-motiveforces produced by said y variable electrical 13. The combination thermo-couple and potentiometer for con-' trolling the space current of said thermionic device, and means controlled by said space current for-adjusting the fall of potential insaid potentiometer to equality with the electro-motive-force: produced by said thermo-couple;

a 14. The combination with a source of current, of electrical means associated therefor determining the magnitude of ourwith rent flowing therefrom,

- thermionic trol the potential of of said thermionic device,

- cal means,

mechanical means.

means, a source of ower for mechanically actuating said mec anical means, and a device electrically controlling connection between said mechanical means and said source of power and responsive to variation of said mechanical means.

15. The combination with a resistance, of mechanical means for, varying the amount of said resistance in a circuit, a thermionic device, a source of power, means for connecting said source of power with said mechanical means and electrically controlled by said thermionic device, said thermionicdevice being controlled in response to variation of said firstnamed mechanical means.

16. The combination with an electrical source, of a thermionic device electrically controlled thereby, variable electrical means opposin' said responsive device, means controlled y said thermionic device for varying said variable electrical means, and a marker simultaneously controlled by said thermionic device.

17. The combination with an electrical source, of a thermionic device electrically controlled thereby and comprising an electrode whose potential controls the magnitude of the space current, variable electrical means cooperating with said source to consaid electrode, means controlled by said thermionic device for varying said variable electrical means, and a marker simultaneously controlled by said thermionic device.

18. The combination with a temperature electrically controlled thereby and comprising an electrode whose potential controls the magnitude of the space current, variable electrical means cooperating with said temperature responsive device to control the potential of said electrode, means controlled by said space current controlling said variable electrical means, and a marker simultaneously controlled by said thermionic device.

20. The combination with 'an' electrical source, of a thermionic device electrically controlled thereby, variable electrical means cooperating with said responsive device in controllin said thermionic device, a source of power or actuating said variable electrimeans controlled by the s ace current or said thermionic device contro ling a marker actusaid source of power, an ated by said source of power.

21. The "combinatiom with an" electrical source, of a thermionic device electrically controlled thereby, variable electrical means cooperating with said electrical source in.

source, of a thermionic device, variable electrical means cooperating with said electrical source in controlling said thermionic device, electro-magnetic means responsive, respectively, to increases and decreases in the space current of said thermionic device, a source of power controlled by said electro-magnetic means for actuating said variable electrical means, and a marker actuated by said source of power.-

23. The combination with means responsive to temperature changes for effecting potential differences, ofa thermionic device electrically controlled thereby and comprising an electrode whose potential controls the space current of said thermionic device, means for producing a vari'able potential in opposition to the potential difference effected by said temperature responsive device and cooperating therewith to control the potential of said electrode, means controlled by said space current controlling said variable means, and a marker controlled by said space current.

24. The combination with a thermionic device having an electrode controlling the space current of said device, a circuit traversed by said space current, a movable member, a source of power, means for connecting said source of power with said movable member to move the same, means controlled by said circuit controlling said connecting means, and means for varying the potential of said electrode.

. 25. The combination with a thermionic device having an electrode whose potential controls the space current, a circuit traversed by said space current, a movable member, means for moving the same, means in said circuit controlling said last named means, and means actuated by said movable member for varying the potential of said electrode.

26. The combination with a thermionic device having an electrode whose potential controls the space current, a circuit traversed by said space current, electro-magnetic means controlled by said circuit, a movable member, a source of. power, means for connecting said source of power with said movable member and controlled by said electromagnetic means, and means for changing the potential of said electrode.

27. The combination with a thermionic device having an electrode whose potential 28. The combination with a thermioni device, of a circuit traversed by the. space current thereof, and means associated with said circuit and responding in opposite directions to changes in opposite directions of said space current comprising normally saturated and unsaturated electro-magnets, and an armature member cooperating therewith.

29. The combination with a source of variable potential, of a thermionic device having an electrode whose potential controlsthe space current of said device, said electrode being connected with said source of variable potential, a movable structure, a source of power, means actuated by said space current controlling actuation of said movable structure by said source of power, and a resistance varied by said movable structure and opposing said variable potential.

30. The combination with a source of variable potential, of a thermionic device having an electrode whose potential controls the space current of said device, said electrode being connected with'said source of variable potential, a movable structure, a source of power, means controlled by said space current connecting said movable structure with said source of power, and a marker moved by said movable structure.

31. The combination with a source of variable jpotentiahof a thermionic device having an electrode whose potential controls the space current of said device, said electrode being connected with said source of variable potential, *a movable structure, a source of power, means controlled by said space current connecting said movable structure with said source of current, a variable resistance opposing variations of said variable potential actuated by said movable structure, and a marker moved by said movable structure.

32. The combination with a source of variable potential, of a thermionic device having an electrode whose potential controls the magnitude of current in the anode circuit of said device, said electrode being subjected to potential variations of said source, a movable structure, a source of power, means controlled by said current controlling actuation of said movable structure by said source of power, and current controlling means operated bysaid movable a movable structure,

v structure.

33. The combination with a source of variable potential, of a thermionic device having an electrode whose potential con trols the magnitude of current in the anode circuit of said device, said electrode being subjected to potential variations of said source, a movable structure, a source of power, means controlled by said current COIltIOlllIlg actuation of said movable structure by said source of power, current controlling means operated by said movable structure and a second source of variable potential opposing said first named source and controlled by said movable structure.

34. The combination with a thermocouple, of a thermionic device having an .electrode whose potential controls the magnitude of current in the anode circuit of said device, said electrode being subjected to voltage variations of sald thermo-couple,

means controlled by said current controlling actuation of said movable structure by said source of power, and a source of variable potential opposing said thermo-couple' and controlled by said movable structure. I

a source of power,

'35. The combination with a thermocouple, of a thermionic device having an electrode whose potential controls the magnitude of current in the anode circuit of said device, said electrode being subjected to variable potential, of a thermionic device having an electrode controlling the current in the anode circuit of said device, the potential of said electrode being controlled by said source, a movable structure, a source of power, means controlling actuation of said movable structure by said source of power, and relay means controlled by the current in the anode circuit of said thermionic device controlling said means.

In testimony whereof I have hereunto affixed my signature this 17th day of May,

HARRY F. PORTER.

a source of variable poten- 

